Regrettably, I'm not sure if anyone on here has significant expertise in 3D modeling. I know a few very basic concepts and have worked through simple tutorials in 3DS Max, but I've never used Blender before.

I'd recommend doing a Google search for solid, beginner-level tutorials. Start with basic things, like how to make shape primitives, what meshes are, UV mapping, and from there, work your way to character rigging and specifics on building low-poly characters. I wish I could give more advice, but I hope that's enough to get started.